1. Field
The present disclosure relates generally to supersonic vehicles and, in particular, to mitigating the undesired effects of traveling at supersonic speeds. Still, more particularly, the present disclosure relates to a method and apparatus for using plasma to mitigate the undesired effects of a vehicle traveling at a speed that is greater than a critical Mach number for the vehicle.
2. Background
A supersonic vehicle is a vehicle that can travel at supersonic speeds, which are speeds that exceed the speed of sound. When a supersonic vehicle approaches and crosses the speed of sound, the effects of the finite viscosity of the air may cause various undesired effects. These undesired effects may include, but are not limited to, undesired shock effects, drag, and undesired heating of the supersonic vehicle. The undesired shock effects may include, for example, bow shock, shear shock, some other type of shock, or some combination thereof, that increases the draft force acting on the supersonic vehicle.
Air plasma is one means of mitigating the undesired effects of traveling at supersonic speeds. Current systems for generating air plasma include using systems that generate, for example, without limitation, electrical corona and discharge and microwave radio frequency (RF) discharge. However, these currently available systems may create air plasma that is heated more than desired. Heated air plasma may cause undesired heating of the supersonic vehicle and may affect the aerodynamic performance of the supersonic vehicle.
Further, these systems may create an undesired signature, such as a radio frequency signature, that may be detectable. Still further, controlling the air plasma that is created downstream may be more difficult than desired using these currently available systems. For example, the air plasma may interfere with the operation of an antenna device or antenna aperture on the supersonic vehicle. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.